Paradoxical experience of hypnotic analgesia in low hypnotizable fibromyalgic patients

The study investigated the differences in pain perception in highly (Highs) and low (Lows) hypnotizable patients with chronic benign pain undergoing hypnotic suggestions of analgesia. Self reports of pain intensity were collected in different groups of fibromyalgic patients: (1) Highs and Lows during pre-hypnosis, neutral hypnosis, suggestions for analgesia, posthypnotic conditions; (2) Lows during suggestions for analgesia administered after a mental stress instead of neutral hypnosis; (3) healthy Lows receiving nociceptive stimulation during hypnotic relaxation and suggestions of analgesia. The results showed that Highs and Lows differed in their response to suggestions, but significant analgesia was reported also by Lows. These individuals did not report any difference in pain perception between the sessions including mental stress and hypnotic relaxation. No change in pain perception was observed in healthy Lows during nociceptive stimulation associated with relaxation and suggestions for analgesia. In conclusion, the presence of chronic pain seems to be responsible for the paradoxical response of non hypnotizable patients to hypnotic suggestions.     

Blood pressure responses to hypnotic and nonhypnotic suggestions in normotensive subjects

Forty normotensive subjects participated on a voluntary basis in a study designed to compare the effect of suggestions on blood pressure (BP). Two experimental groups received suggestions presumed to be specific in lowering or raising BP after simple relaxation (relaxation group) or hypnotic induction (hypnotic group). A control group was used to record the BP changes over time. The time variable was significant for both systolic (SBP) and diastolic blood pressure (DBP). Induction procedures (hypnosis or relaxation) resulted in significant decreases in DBP in both experimental groups. In the control group there was a significant decrease in SBP. A specific suggestion to increase the BP resulted only in DBP increase in the hypnotic group. This group also gave an increase of both SBP and DBP over the entire experiment, whereas the relaxation group resulted in a significant decrease in SBP. There was no significant group variable, indicating no differences between the groups. Further research is needed to enable firm conclusions of the effect of suggestions on BP.     

Desynchronization of Theta-Phase Gamma-Amplitude Coupling during a Mental Arithmetic Task in Children with Attention Deficit/Hyperactivity Disorder

Introduction

Theta-phase gamma-amplitude coupling (TGC) measurement has recently received attention as a feasible method of assessing brain functions such as neuronal interactions. The purpose of this electroencephalographic (EEG) study is to understand the mechanisms underlying the deficits in attentional control in children with attention deficit/hyperactivity disorder (ADHD) by comparing the power spectra and TGC at rest and during a mental arithmetic task.

Methods

Nineteen-channel EEGs were recorded from 97 volunteers (including 53 subjects with ADHD) from a camp for hyperactive children under two conditions (rest and task performance). The EEG power spectra and the TGC data were analyzed. Correlation analyses between the Intermediate Visual and Auditory (IVA) continuous performance test (CPT) scores and EEG parameters were performed.

Results

No significant difference in the power spectra was detected between the groups at rest and during task performance. However, TGC was reduced during the arithmetic task in the ADHD group compared with the normal group (F = 16.70, p < 0.001). The TGC values positively correlated with the IVA CPT scores but negatively correlated with theta power.

Conclusions

Our findings suggest that desynchronization of TGC occurred during the arithmetic task in ADHD children. TGC in ADHD children is expected to serve as a promising neurophysiological marker of network deactivation during attention-demanding tasks.     

Cognitive Modulation of Psychophysical,Respiratory and Autonomic Responses to Cold Pressor Test

In healthy subjects with high hypnotisability (highs) under hypnosis, subjectively effective suggestions for analgesia abolish the increases in blood pressure associated with cold pressor test (cpt) by reducing the peripheral vascular resistance. The aim of the present study was to investigate the effects of the suggestions of analgesia on the responses to cpt in healthy highs (n = 22) and in low hypnotisable participants (lows, n = 22) out of hypnosis. Cpt was administered without (CPT) and with suggestions for analgesia (CPT+AN). Psychophysical (pain intensity, pain threshold, cpt duration (time of immersion) and pain tolerance, defined as the difference between cpt duration and pain threshold), respiratory (amplitude and frequency) and autonomic variables (tonic skin conductance, mean RR interval (RR = 1/heart rate), blood pressure, skin blood flow) were studied. The suggestions for analgesia increased cpt duration and RR in both groups, but decreased pain intensity and enhanced pain threshold only in highs; in both groups they did not modulate systolic blood pressure, tonic skin conductance and skin blood flow; thus, increased parasympathetic activity appears responsible for the heart rate reduction induced by suggestions in both groups. In conclusion, our findings show that suggestions modulate pain experience differentially in highs and lows, and are partially effective also in lows. We hypothesize that the mechanisms responsible for the efficacy of suggestions in healthy lows may be involved also in their efficacy in chronic pain patients with low hypnotisability.     

JM-1232(−) and propofol,a new combination of hypnotics with short-acting and non-cumulative preferable properties

Drug interactions are significant in anesthesiology because drug combinations can potentially possess novel properties. The pharmacological advantages of a new combination of the benzodiazepine receptor agonist JM-1232(−) and propofol were investigated in mice. Male adult mice were administered JM-1232(−) or propofol or combinations of the two drugs intravenously. Loss of the righting reflex was evaluated as achieving hypnosis, and the time until recovery of the reflex was measured as hypnosis time. After determining the ED₅₀, doses double and triple the ED₅₀ of propofol were injected with JM-1232(−) to compare hypnosis time. The injections were repeated four times, and the hypnosis times were compared. Flumazenil was administered separately immediately after the last dose was injected. The ED₅₀ values ([95% confidence interval]) for hypnosis were 3.76 [3.36–4.10] for JM-1232(−) and 9.88 [8.03–11.58] mg kg⁻¹ for propofol. Co-administration of 0.5 and 1 mg kg⁻¹ JM-1232(−) reduced the ED₅₀ values of propofol to 1.76 [1.21–2.51] and 1.00 [0.46–1.86] mg kg⁻¹, respectively. The drug combination for hypnosis produced a supra-additive interaction. Hypnosis time was significantly shorter in the groups given the mixtures compared to each hypnotic administered alone. After repeated injections, hypnosis time with the mixtures showed smaller prolongation than that with the hypnotic alone. Flumazenil completely restored the recovery time after anesthesia. The combination of JM-1232(−) and propofol showed a supra-additive interaction, and the reduced hypnotic dose contributed to a faster recovery even after multiple injections.     

Flanker performance in female college students with ADHD: a diffusion model analysis

Attention-deficit hyperactivity disorder (ADHD) is characterized by poor adaptation to environmental demands, which leads to various everyday life problems. The present study had four aims: (1) to compare performance in a flanker task in female college students with and without ADHD (N = 39) in a classical analyses of reaction time and error rate and studying the underlying processes using a diffusion model, (2) to compare the amount of focused attention, (3) to explore the adaptation of focused attention, and (4) to relate adaptation to psychological functioning. The study followed a 2-between (group: ADHD vs. control) × 2-within (flanker conflict: incongruent vs. congruent) × 2-within (conflict frequency: 20 vs. 80 %) design. Compared to a control group, the ADHD group displayed prolonged response times accompanied by fewer errors in a flanker task. Results from the diffusion model analyses revealed that the members of the ADHD group showed deficits in non-decisional processes (i.e., higher non-decision time) and leaned more toward accuracy than participants without ADHD (i.e., setting higher boundaries). The ADHD group showed a more focused attention and less adaptation to the task conditions which is related to psychological functioning. Deficient non-decisional processes and poor adaptation are in line with theories of ADHD and presumably typical for the ADHD population, although this has not been shown using a diffusion model. However, we assume that the cautious strategy of trading speed of for accuracy is specific to the subgroup of female college students with ADHD and might be interpreted as a compensation mechanism.     

Does hypnotizability affect human upright stance?

Subjects highly (Highs) and low susceptible to hypnosis (Lows) show different imagery and attentional capabilities and also peculiar somatomotor, vegetative and electroencephalographic differences in basal and task conditions. Since attention is one of the main component of hypnotic susceptibility and also a relevant factor for postural control, the aim of the experiment was to study actual differences between Highs and Lows at the eyes closure during upright stance. Visual and motor imagery as well as attentional/disattentional capabilities were evaluated through psychological tests. Posture was monitored though Elite systems during upright stance with open and closed eyes. At the eyes closure, Highs and Lows exhibited a different body sway modulation. Possible different compensation mechanisms are suggested for the two groups and interactions between attentional/arousal systems responsible of hypnotic phenomenology and postural control are underlined.     

Early maladaptive schemas in adult patients with attention deficit hyperactivity disorder

The main purpose of this study was to examine whether adult patients with attention deficit hyperactivity disorder (ADHD) demonstrate sets of dysfunctional cognitive beliefs and behavioural tendencies according to Jeffrey Young’s schema-focused therapy model. Sets of dysfunctional beliefs (maladaptive schemas) were assessed with the Young Schema Questionnaire (YSQ-S2) in 78 adult ADHD patients and 80 control subjects. Patients with ADHD scored significantly higher than the control group on almost all maladaptive schemas. The ‘Failure’, ‘Defectiveness/Shame’, ‘Subjugation’ and ‘Emotional Deprivation’ schemas were most pronounced in adult ADHD patients, while only ‘Vulnerability to Harm or Illness’ did not differ between the two groups. The schemas which were most pronounced in adult patients with ADHD correspond well with their learning histories and core symptoms. By demonstrating the existence of early maladaptive schemas in adults suffering from ADHD, this study suggests that schema theory may usefully be applied to adult ADHD therapy.     

Improvement in bronchial hyper-responsiveness in patients with moderate asthma after treatment with a hypnotic technique: a randomised controlled trial.

A prospective, randomised, single blind, and controlled trial of a hypnotic technique was undertaken in 39 adults with mild to moderate asthma graded for low and high susceptibility to hypnosis. After a six week course of hypnotherapy 12 patients with a high susceptibility score showed a 74.9% improvement (p less than 0.01) in the degree of bronchial hyper-responsiveness to a standardised methacholine challenge test. Daily home recordings of symptoms improved by 41% (p less than 0.01), peak expiratory flow rates improved by 5.5% (p less than 0.01), and use of bronchodilators decreased by 26.2% (p less than 0.05). The improvement in bronchial hyper-reactivity occurred without a change in subjective appreciation of the degree of bronchoconstriction. A control group 17 patients and 10 patients undergoing treatment with low susceptibility to hypnosis had no change in either bronchial hyper-responsiveness or any of the symptoms recorded at home. This study shows the efficacy of a hypnotic technique in adult asthmatics who are moderately to highly susceptible to hypnosis.     

Dissociable Patterns in the Control of Emotional Interference in Adults with Attention-Deficit/Hyperactivity Disorder (ADHD) and in Adults with Alcohol Dependence

Objectives

To effectively manage current task demands, attention must be focused on task-relevant information while task-irrelevant information is rejected. However, in everyday life, people must cope with emotions, which may interfere with actual task demands and may challenge functional attention allocation. Control of interfering emotions has been associated with the proper functioning of the dorsolateral prefrontal cortex (DLPFC). As DLPFC dysfunction is evident in subjects with ADHD and in subjects with alcohol dependence, the current study sought to examine the bottom-up effect of emotional distraction on task performance in both disorders.

Methods

Male adults with ADHD (n = 22), male adults with alcohol dependence (n = 16), and healthy controls (n = 30) performed an emotional working memory task (n-back task). In the background of the task, we presented neutral and negative stimuli that varied in emotional saliency.

Results

In both clinical groups, a working memory deficit was evident. Moreover, both clinical groups displayed deficient emotional interference control. The n-back performance of the controls was not affected by the emotional distractors, whereas that of subjects with ADHD deteriorated in the presence of low salient distractors, and that of alcoholics did not deteriorate until high salient distractors were presented. Subsequent to task performance, subjects with ADHD accurately recognized more distractors than did alcoholics and controls. In alcoholics, picture recognition accuracy was negatively associated with n-back performance, suggesting a functional association between the ability to suppress emotional distractors and successful task performance. In subjects with ADHD, performance accuracy was negatively associated with ADHD inattentive symptoms, suggesting that inattention contributes to the performance deficit.

Conclusions

Subjects with ADHD and alcoholics both display an emotional interference control deficit, which is especially pronounced in subjects with ADHD. Beyond dysfunctional attention allocation processes, a more general attention deficit seems to contribute to the more pronounced performance deficit pattern in ADHD.     

Effects of Correct and Wrong Answers on ERPs Recorded under Conditions of the Continuous Performance Test in ADHD/Normal Participants

Parameters of event-related potentials (ERPs) regarding correct and wrong answers under conditions of the continuous performance test (CPT) were measured in 50 adult subjects characterized by different levels of sustained attention with the absence/presence of attention deficit/hyperactivity disorders (ADHD). For ERP extraction, the average for each group of signals, which were time-locked to the onset of stimuli, was calculated; two ERP groups were considered separately for correct and wrong answers. In both groups, the P300 wave was clearly observed. The time dynamics of ERP components were investigated in six defined time blocks. At the peak of P300, a prominent component of brain activity could be observed. Some ERP morphological features (704 items) were extracted from these potentials. The results indicated that 11 of the obtained features showed a significant (P < 0.01) relation to the level of sustained attention. When comparing correct and wrong answers, 10 features in the normal group and 3 features in the ADHD group demonstrated significant differences (P < 0.05), which means that the participant’s response is reflected in the features of EEG signal. The results reveal a promising relation between CPT results and some parameters of brain signals, which can be used for further evaluations of the sustained attention level.     

Attention-induced deactivations in very low frequency EEG oscillations: differential localisation according to ADHD symptom status

Background

The default-mode network (DMN) is characterised by coherent very low frequency (VLF) brain oscillations. The cognitive significance of this VLF profile remains unclear, partly because of the temporally constrained nature of the blood oxygen-level dependent (BOLD) signal. Previously we have identified a VLF EEG network of scalp locations that shares many features of the DMN. Here we explore the intracranial sources of VLF EEG and examine their overlap with the DMN in adults with high and low ADHD ratings.

Methodology/Principal Findings

DC-EEG was recorded using an equidistant 66 channel electrode montage in 25 adult participants with high- and 25 participants with low-ratings of ADHD symptoms during a rest condition and an attention demanding Eriksen task. VLF EEG power was calculated in the VLF band (0.02 to 0.2 Hz) for the rest and task condition and compared for high and low ADHD participants. sLORETA was used to identify brain sources associated with the attention-induced deactivation of VLF EEG power, and to examine these sources in relation to ADHD symptoms. There was significant deactivation of VLF EEG power between the rest and task condition for the whole sample. Using s-LORETA the sources of this deactivation were localised to medial prefrontal regions, posterior cingulate cortex/precuneus and temporal regions. However, deactivation sources were different for high and low ADHD groups: In the low ADHD group attention-induced VLF EEG deactivation was most significant in medial prefrontal regions while for the high ADHD group this deactivation was predominantly localised to the temporal lobes.

Conclusions/Significance

Attention-induced VLF EEG deactivations have intracranial sources that appear to overlap with those of the DMN. Furthermore, these seem to be related to ADHD symptom status, with high ADHD adults failing to significantly deactivate medial prefrontal regions while at the same time showing significant attenuation of VLF EEG power in temporal lobes.     

ERP Correlates of Proactive and Reactive Cognitive Control in Treatment-Na?ve Adult ADHD

This study investigated whether treatment naïve adults with Attention Deficit Hyperactivity Disorder (ADHD; n = 33; 19 female) differed from healthy controls (n = 31; 17 female) in behavioral performance, event-related potential (ERP) indices of preparatory attention (CueP3 and late CNV), and reactive response control (Go P3, NoGo N2, and NoGo P3) derived from a visual cued Go/NoGo task. On several critical measures, Cue P3, late CNV, and NoGo N2, there were no significant differences between the groups. This indicated normal preparatory processes and conflict monitoring in ADHD patients. However, the patients had attenuated Go P3 and NoGoP3 amplitudes relative to controls, suggesting reduced allocation of attentional resources to processes involved in response control. The patients also had a higher rate of Go signal omission errors, but no other performance decrements compared with controls. Reduced Go P3 and NoGo P3 amplitudes were associated with poorer task performance, particularly in the ADHD group. Notably, the ERPs were not associated with self-reported mood or anxiety. The results provide electrophysiological evidence for reduced effortful engagement of attentional resources to both Go and NoGo signals when reactive response control is needed. The absence of group differences in ERP components indexing proactive control points to impairments in specific aspects of cognitive processes in an untreated adult ADHD cohort. The associations between ERPs and task performance provided additional support for the altered electrophysiological responses.     

Pain Modulation in Waking and Hypnosis in Women: Event-Related Potentials and Sources of Cortical Activity

Using a strict subject selection procedure, we tested in High and Low Hypnotizable subjects (HHs and LHs) whether treatments of hypoalgesia and hyperalgesia, as compared to a relaxation-control, differentially affected subjective pain ratings and somatosensory event-related potentials (SERPs) during painful electric stimulation. Treatments were administered in waking and hypnosis conditions. LHs showed little differentiation in pain and distress ratings between hypoalgesia and hyperalgesia treatments, whereas HHs showed a greater spread in the instructed direction. HHs had larger prefrontal N140 and P200 waves of the SERPs during hypnotic hyperalgesia as compared to relaxation-control treatment. Importantly, HHs showed significant smaller frontocentral N140 and frontotemporal P200 waves during hypnotic hypoalgesia. LHs did not show significant differences for these SERP waves among treatments in both waking and hypnosis conditions. Source localization (sLORETA) method revealed significant activations of the bilateral primary somatosensory (BA3), middle frontal gyrus (BA6) and anterior cingulate cortices (BA24). Activity of these contralateral regions significantly correlated with subjective numerical pain scores for control treatment in waking condition. Moreover, multivariate regression analyses distinguished the contralateral BA3 as the only region reflecting a stable pattern of pain coding changes across all treatments in waking and hypnosis conditions. More direct testing showed that hypnosis reduced the strength of the association of pain modulation and brain activity changes at BA3. sLORETA in HHs revealed, for the N140 wave, that during hypnotic hyperalgesia, there was an increased activity within medial, supramarginal and superior frontal gyri, and cingulated gyrus (BA32), while for the P200 wave, activity was increased in the superior (BA22), middle (BA37), inferior temporal (BA19) gyri and superior parietal lobule (BA7). Hypnotic hypoalgesia in HHs, for N140 wave, showed reduced activity within medial and superior frontal gyri (BA9,8), paraippocampal gyrus (BA34), and postcentral gyrus (BA1), while for the P200, activity was reduced within middle and superior frontal gyri (BA9 and BA10), anterior cingulate (BA33), cuneus (BA19) and sub-lobar insula (BA13). These findings demonstrate that hypnotic suggestions can exert a top-down modulatory effect on attention/preconscious brain processes involved in pain perception.     

Neurocognitive correlates of adult attention-deficit/hyperactivity disorder in a Turkish sample

We established a neuropsychological testing profile among Turkish adults presenting with ADHD controlling for general intelligence and comorbid psychiatric conditions. Adults with ADHD frequently present with comorbid conditions (e.g., mood and substance use/abuse disorders) that may have a detrimental impact on neurocognitive function. Hence, we excluded patients with ADHD meeting criteria for comorbid psychiatric syndromes. A comprehensive neuropsychological test battery was administered to adults with ADHD attending a general psychiatry clinic in Istanbul, Turkey, and healthy control participants. Adults with ADHD demonstrated performance deficits on tests of attention, information processing speed, and general and working memory. Patients with ADHD also reported a significantly greater number of symptoms associated with frontal lobe syndromes (i.e., dysexecutive symptoms and disinhibition). Patients with ADHD demonstrated rather striking deficits on tests of verbal and nonverbal memory. Once information was encoded, however, patients with ADHD do not demonstrate significant information loss. Patients with ADHD and healthy controls did not differ on tests of alternation learning, inhibitory control (error rates), and ToM skills. Findings support the contention that dorsal-prefrontal (rather than ventral-prefrontal) dysfunction is associated with adult ADHD. Unexpectedly, groups did not differ on executive control and fluency tasks. Yet patients with ADHD obtained substantially higher scores on a self-report measure of executive dysfunction. This suggests that dysexecutive symptoms among patients with ADHD in the current study do not reflect set-shifting or organizational deficits. Rather, symptoms may reflect attentional and working memory deficits as well as diminished information processing speed.     

Detection of malingered attention deficit hyperactivity disorder

The aim of the present study was to determine whether malingering of adult attention deficit hyperactivity disorder (ADHD) can be detected using a self-report rating scale. A sample of 78 university students was allocated to three different conditions. The conditions were (a) a control group, (b) a na?ve simulation group and (c) a coached simulation group. Furthermore, 12 adult students with a diagnosed ADHD participated in the present study. Participants were administered the Brown Attention Deficit Disorder Scale for Adults. While the control group and the patient group were asked to complete the scale with accuracy, the simulation groups were requested to feign an ADHD. Statistical analysis revealed that both simulation groups were able to successfully feign an ADHD. The results indicate that self-report rating measures are not sensitive enough to allow the detection of feigned ADHD.     

Gender differences in self- and investigator-rated psychopathology in adult attention-deficit/hyperactivity disorder

Despite the growing interest in the diagnosis of ADHD in adults, most of the knowledge in ADHD still relies on research with children and adolescents. Gender differences in adult ADHD patients were neglected for a long time and only few studies have focused this topic. The goal of this study was to investigate differences in ADHD psychopathology in male and female adults. We examined gender differences in ADHD core and associated symptoms and in personality traits in adults with ADHD. In order to discriminate between general and ADHD-specific gender differences, we compared data of adult ADHD patients with two control groups (patients with substance abuse and healthy controls). Regarding differences in ADHD core symptoms-attention problems, hyperactivity, and impulsivity-between male and female subjects, we found inconsistent results depending on the applied diagnostic instruments. Using standardized self-report, there were no gender differences regarding attention problems and hyperactivity but regarding impulsivity. Results of a semi-standardized interview (WRAADDS) according to the Utah criteria of adult ADHD showed no gender differences regarding impulsivity and hyperactivity but regarding attention problems. Moreover, differences were found between female and male healthy controls in the domains "over reactivity" and "hot temper" but not in the group of ADHD patients. Thus, it seems that gender differences in normal population were leveled by the disorder. Concerning general personality traits, some differences between male and female ADHD patients were also present in healthy controls, suggesting no ADHD-specific effect of gender. In conclusion, male and female ADHD patients seem to be more similar than different regarding ADHD-related psychopathology and general personality traits.     

Attention-Related Eye Vergence Measured in Children with Attention Deficit Hyperactivity Disorder

Recent evidence shows a novel role for eye vergence in orienting attention in adult subjects. Here we investigated whether such modulation in eye vergence by attention is present in children and whether it is altered in children with ADHD compared to control subjects. We therefore measured the angle of eye vergence in children previously diagnosed with ADHD while performing a cue task and compared the results to those from age-matched controls. We observed a strong modulation in the angle of vergence in the control group and a weak modulation in the ADHD group. In addition, in the control group the modulation in eye vergence was different between the informative cue and uninformative cue condition. This difference was less noticeable in the ADHD group. Our study supports the observation of deficient binocular vision in ADHD children. We argue that the observed disruption in vergence modulation in ADHD children is manifest of altered cognitive processing of sensory information. Our work may provide new insights into attention disorders, like ADHD.     

The Use of Hypnosis in the Treatment of Exhibitionism

The use of hypnosis in the treatment of exhibitionism is described in three patients in whom the condition had been present for more than five years. In each patient there was no subsequent recurrence of the exhibitionism once therapeutic suggestions had been made in a deep hypnotic trance, the follow-up period being respectively five years, four and a half years, and one year.The method of treatment and the results are discussed in terms of the concepts of behaviour therapy.It is concluded that with certain patients suffering from exhibitionism the use of hypnosis may well be one of the best methods of treatment, but considerable care should be exercised to exclude those patients with an underlying psychosis, mental defect or psychopathic condition. It is also noted that the efficacy of the treatment would appear to depend on achieving a satisfactory depth of hypnotic trance. If this is not reached, the results are less likely to be successful.     

The existence of a hypnotic state revealed by eye movements

Hypnosis has had a long and controversial history in psychology, psychiatry and neurology, but the basic nature of hypnotic phenomena still remains unclear. Different theoretical approaches disagree as to whether or not hypnosis may involve an altered mental state. So far, a hypnotic state has never been convincingly demonstrated, if the criteria for the state are that it involves some objectively measurable and replicable behavioural or physiological phenomena that cannot be faked or simulated by non-hypnotized control subjects. We present a detailed case study of a highly hypnotizable subject who reliably shows a range of changes in both automatic and volitional eye movements when given a hypnotic induction. These changes correspond well with the phenomenon referred to as the "trance stare" in the hypnosis literature. Our results show that this 'trance stare' is associated with large and objective changes in the optokinetic reflex, the pupillary reflex and programming a saccade to a single target. Control subjects could not imitate these changes voluntarily. For the majority of people, hypnotic induction brings about states resembling normal focused attention or mental imagery. Our data nevertheless highlight that in some cases hypnosis may involve a special state, which qualitatively differs from the normal state of consciousness.